I'll avoid any that have been mentioned:
Two semi-obscure period WW II films I have seen a few times and continue to enjoy:
The Cruel Sea
Ice Cold in Alex
An art film: The Dreamers
Why? Young Eva Green, of course!
Another good movie though it deviates from the the Milan Kundera novel:
The Unbearable Lightness of Being
Anything by Quentin Tarrantino, but especially his recent dark comedy, Once Upon a Time in Hollywood.
Leo DeCaprio, Brad Pitt and Magot Robbie are at their best . . . and others in supporting roles are very good.